.btob-challenges-section {
  position: relative;
  padding: clamp(3.5rem, 7vw, 6rem) 0;
}

.btob-challenges-section .sector-section__inner {
  max-width: 1180px;
}

.btob-section-header {
  max-width: 47rem;
  margin-bottom: clamp(1.8rem, 4vw, 3rem);
}

.btob-section-header p {
  margin: 0 0 1rem;
  color: #6d5dfc;
  font-size: 0.84rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.btob-section-header h2 {
  margin: 0;
  color: var(--sector-text);
  font-size: clamp(2rem, 4vw, 3.15rem);
  font-weight: 900;
  line-height: 1.03;
  letter-spacing: 0;
}

.btob-section-header span {
  display: block;
  max-width: 38rem;
  margin-top: 0.9rem;
  color: var(--sector-muted);
  font-size: clamp(1rem, 1.7vw, 1.13rem);
  line-height: 1.62;
}

.btob-challenges-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: clamp(1rem, 2vw, 1.5rem);
}

.btob-challenge-card {
  min-height: 18rem;
  border: 1px solid rgba(167, 139, 250, 0.2);
  border-radius: 1rem;
  padding: clamp(1.35rem, 2.2vw, 2rem);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.9), rgba(255, 255, 255, 0.66)),
    radial-gradient(circle at 50% 0%, rgba(109, 93, 252, 0.12), transparent 66%);
  box-shadow: 0 22px 58px rgba(76, 62, 181, 0.1);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}

.btob-challenge-card__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 4.35rem;
  height: 4.35rem;
  border-radius: 1.25rem;
  background: linear-gradient(180deg, rgba(237, 233, 254, 0.96), rgba(221, 214, 254, 0.78));
  color: #6d5dfc;
  font-size: 1.65rem;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.82);
}

.btob-challenge-card h3 {
  margin: 1.55rem 0 0;
  color: var(--sector-text);
  font-size: clamp(1.05rem, 1.45vw, 1.18rem);
  font-weight: 850;
  line-height: 1.2;
  letter-spacing: 0;
}

.btob-challenge-card p {
  margin: 1rem 0 0;
  color: var(--sector-muted);
  font-size: 0.95rem;
  line-height: 1.55;
}

.sector-page.sector-theme-dark .btob-challenge-card {
  border-color: rgba(167, 139, 250, 0.22);
  background:
    radial-gradient(circle at 50% 120%, rgba(76, 62, 181, 0.24), transparent 70%),
    rgba(18, 11, 34, 0.62);
  box-shadow: 0 16px 34px rgba(76, 29, 149, 0.14);
}

.sector-page.sector-theme-dark .btob-challenge-card__icon {
  background: rgba(255, 255, 255, 0.08);
  color: #8b5cf6;
}

.sector-page.sector-theme-dark .btob-section-header h2,
.sector-page.sector-theme-dark .btob-challenge-card h3 {
  color: #ffffff;
}

.sector-page.sector-theme-dark .btob-section-header span,
.sector-page.sector-theme-dark .btob-challenge-card p {
  color: #c7c2d9;
}

@media (max-width: 980px) {
  .btob-challenges-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 640px) {
  .btob-challenges-grid {
    grid-template-columns: 1fr;
  }
}